Shoe having photoreactive components

ABSTRACT

A shoe having photoreactive components, such as a sole, a heel, and/or a series of straps. Each photoreactive component is made from a mixture of a base material, such as rubber, plastic, or polymer, and a photoreactive composition, such as a spiropyran compound or a spirooxazine compound. When exposed to ultraviolet light, the photoreactive components of the shoe reversibly change color.

BACKGROUND OF THE INVENTION

This invention relates to shoes having photoreactive components. More particularly, this invention relates to shoe soles and straps which have photoreactive compositions mixed into the components themselves, so that the components change color when exposed to ultraviolet light.

There have been previous attempts at creating shoes having designs which change from colorless to a particular color, or from one color to another, upon exposure to ultraviolet light. However, these previous attempts essentially consist of attaching photoreactive designs to existing shoes. For example, one such shoe utilizes screen-printing to apply a photoreactive design. Another relies upon the application of a separate photoreactive panel by stitching or an adhesive. There is not, however, a shoe that has components, such as soles and/or straps, that are photoreactive themselves, instead of having photoreactive designs applied thereto.

It therefore would be desirable to provide a shoe that has components which themselves are photoreactive, so that the components change color when exposed to ultraviolet light.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a shoe having photoreactive soles and/or straps that reversibly change color when exposed to ultraviolet light.

It is another object of the present invention to provide a shoe having soles and/or straps that are photoreactive themselves, without a need to apply additional designs or materials to achieve a photoreactive effect.

In accordance with the present invention, a shoe or other article of footwear having photoreactive components is provided. A base material of a sole of the shoe may be plastic, rubber, polymer, or any other suitable material capable of being mixed with a photoreactive composition. The shoe also may have one or more straps, located near a wearer's heel or instep and/or at any other location, also made of any such suitable material.

At least one of a number of different photoreactive compositions may be mixed with the plastic, rubber, polymer, or other base material used to create the sole and/or straps of the shoe. For example, the photoreactive composition may be a spiropyran or spirooxazine composition. The effect of such mixing is that the shoe's sole and/or straps themselves will change color, or become a color if initially transparent, when exposed to ultraviolet light. Additional elements may be mixed with the base material and the photoreactive composition as well, including but not limited to an ultraviolet stabilizer or an antioxidant.

The above and other objects, features, and advantages of the present invention will become apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings in which like reference characters refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a perspective view of a first preferred embodiment of a shoe having photoreactive components according to the present invention.

FIG. 2A and 2B illustrate several illustrative chemical compounds that may be used as the photoreactive composition in accordance with any preferred embodiment of the present invention.

FIG. 3 shows a perspective view of a second preferred embodiment of a shoe having photoreactive components according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is directed to an article of footwear, which may be any type of shoe, sneaker, sandal, boot, or other article worn on a foot. By way of example, FIG. 1 shows a men's sneaker 1 in accordance with the present invention, and FIG. 3 shows a women's casual shoe 101 in accordance with the present invention.

As shown in FIG. 1, a sneaker 1 may be composed of a sole 10, an upper portion 20, laces 30, and one or more optional straps 40. Sole 10 may be made of a base material such as plastic, rubber, polymer, or any other suitable material, which has been mixed with a photoreactive composition as discussed below. Upper portion 20 may be attached to sole 10 to complete the sneaker's shape, as shown, and may be made of leather, canvas, or any other suitable sneaker material. Laces 30 may be threaded through a series of eyelets 35 so that they may be tied to secure sneaker 1 on a wearer's foot.

Optional strap 40 may be attached to sneaker 1 over or above eyelets 35 to further secure sneaker 1 on a wearer's foot. Strap 40 may be attached above one row of eyelets 35, pass through a loop 45 attached above the other row of eyelets 35, double back on itself, and be secured using a hook-and-loop type fastener as shown; other methods of fastening a strap also may be used. Strap 40 may be made of a base material such as plastic, rubber, polymer, or another material capable of being mixed with a photoreactive composition as discussed below.

At least one of a number of different photoreactive compositions that are known in the art may be mixed with the plastic, rubber, polymer, or other base material to form sole 10 and/or strap 40 of sneaker 1. Among the known photoreactive compositions are a family of molecules known as spiropyrans, or trimethylindolinospirobenzopyran, such as 1′,3′,3′-trimethylspiro [2H-1-benzopyran-2,2′-indoline]. Another group of known photoreactive compositions are spirooxazines, including 1′,3′,3′, trimethylspiroH[2H-1,4-benzoxazine-2,2′-indoline], or BISO; 1′,3′,3′-trimethylspiro [indoline-2′,3′-[3 H]naphtha[2,1-b][1,4]oxazine]; 3-ethyl-9′methoxy-1,3-dimethylspiro[indoline-2,3′-[3 H]naphth-[2,1-b] [1,4]oxazine], or BISO; 1′,3′,3′-trimethylspiro[indoline-2,3′-[3H]pyrido[3,2-f]-[1,4]benzoxazine, or QISO; and oxazilidinospirooxazine.

Each of these molecules changes either from optical transparency to a predefined color, or from one predefined color to another, when exposed to ultraviolet light. When removed from an ultraviolet light source, the molecules return to their original colors. FIG. 2 shows two specific examples of the chemical changes undergone by such molecules upon exposure to ultraviolet light. FIG. 2A shows the transformation undergone by a spiropyran, and FIG. 2B shows the transformation undergone by a spirooxazine, when each is exposed to ultraviolet light.

The base material and the photoreactive composition that make up sole 10 and/or strap 40 may be mixed and then formed using any methods known in the art. For example, the photoreactive composition may be mixed in powdered form into a collection of rubber or polymer pellets, and such mixture then may be injection-molded into the desired shape. There are, of course, numerous methods known for forming plastic, rubber or polymers into shapes such as shoe soles and straps, and any such method may be utilized.

The photoreactive composition may ideally make up between 10% and 90% of the base material-photoreactive composition mixture by weight. Greater amounts of photoreactive composition in the mixture will result in brighter colors being visible upon exposure to ultraviolet light. The photoreactive composition may make up as little as 10% of the mixture by weight; any less and there is a risk that the color change will not be visible. Furthermore, the photoreactive composition may make up as much as 90% of the mixture by weight, but exceeding that amount risks compromising the properties of the base material.

Additionally, other materials may be added to the mixture of the base material and the photoreactive composition, such as ultraviolet stabilizers or antioxidants. These additional materials may serve to increase the amount of time that the photoreactive composition lasts. If used, the ultraviolet stabilizers and/or antioxidants may total up to 10% by weight of the photoreactive composition, or up to 90% by weight of the base material-photoreactive composition mixture.

When sneaker 1 is exposed to ultraviolet light, sole 10 and any optional straps 40 will change from transparent to a predefined color, or from their original color to a new, predefined color. Upon removal of the ultraviolet light source, sole 10 and optional straps 40 will return to their original color or state of transparency.

FIG. 3 shows another preferred embodiment of the present invention. A woman's casual shoe 101 may be composed of a sole 110, a heel 120, and a series of straps 140, all of which may be made of a base material, such as plastic or polymer or another material, which has been mixed with a photoreactive composition as discussed below. Heel 120 may be joined to sole 110, and straps 140 may be attached to sole 110 and heel 120 to define an opening capable of accepting and fitting a foot. Shoe 101 also may contain one or more buckles or other means for securing shoe 101 to a wearer's foot (not shown).

As above, at least one of a number of different photoreactive compositions that are known in the art may be mixed with the plastic, polymer, or other base material to form sole 110, heel 120 and/or straps 140 of shoe 101, including one of the spiropyrans or spirooxazines families of molecules. The base materials and photoreactive compositions may be mixed and formed as above, using the same proportional limits described in connection with the first embodiment of the invention already described. Additionally, other materials such as ultraviolet stabilizers or antioxidants may be added to the base material-photoreactive composition mixture as described above.

When shoe 101 is exposed to ultraviolet light, sole 110, heel 120, and/or straps 140 will change from transparent to a predefined color, or from their original color to a new, predefined color. Upon removal of the ultraviolet light source, sole 110, heel 120 and/or straps 140 will return to their original color or state of transparency.

Thus, a shoe or other article of footwear having photoreactive elements is provided. Persons skilled in the art will appreciate that the described embodiments are presented for the purpose of illustration rather than limitation and the present invention is limited only by the claims that follow. 

1. An article of footwear, wherein a sole of said article of footwear comprises a base material mixed with a photoreactive composition, so that said sole reversibly changes color when exposed to ultraviolet light.
 2. The article of footwear of claim 1, wherein said photoreactive composition is selected from the group consisting of spiropyran and spirooxazine compounds.
 3. The article of footwear of claim 2, wherein said photoreactive composition comprises between 10% and 90% of the total weight of the mixture of said base material and said photoreactive compound.
 4. The article of footwear of claim 2, wherein said base material is rubber.
 5. The article of footwear of claim 2, wherein said base material is plastic.
 6. The article of footwear of claim 2, wherein said base material is a polymer.
 7. The article of footwear of claim 1, wherein said sole further comprises a means for extending the useful life of said photoreactive composition.
 8. The article of footwear of claim 1, further comprising at least one fastening strap which comprises a second base material and a second photoreactive composition, so that said strap reversibly changes color when exposed to ultraviolet light.
 9. The article of footwear of claim 8, wherein said second photoreactive composition is selected from the group consisting of spiropyran and spirooxazine compounds.
 10. The article of footwear of claim 9, wherein said second photoreactive composition comprises between 10% and 90% of the total weight of the mixture of said second base material and said second photoreactive compound.
 11. The article of footwear of claim 8, wherein said strap further comprises a means for extending the useful life of said second photoreactive composition.
 12. The article of footwear of claim 1, further comprising a heel which comprises a second base material and a second photoreactive composition, so that said heel reversibly changes color when exposed to ultraviolet light.
 13. The article of footwear of claim 12, wherein said second photoreactive composition is selected from the group consisting of spiropyran and spirooxazine compounds.
 14. The article of footwear of claim 13, wherein said second photoreactive composition comprises between 10% and 90% of the total weight of the mixture of said second base material and said second photoreactive compound.
 15. The article of footwear of claim 12, wherein said heel further comprises a means for extending the useful life of said second photoreactive composition.
 16. An article of footwear having at least one fastening strap, wherein said strap comprises a base material mixed with a photoreactive composition, so that said strap reversibly changes color when exposed to ultraviolet light.
 17. The article of footwear of claim 16, wherein said photoreactive composition is selected from the group consisting of spiropyran and spirooxazine compounds.
 18. The article of footwear of claim 17, wherein said photoreactive composition comprises between 10% and 90% of the total weight of the mixture of said base material and said photoreactive compound.
 19. The article of footwear of claim 19, wherein said strap further comprises a means for extending the useful life of said photoreactive composition. 